Movie clip placement via browser

Hey Smart People,

OK, after an endless amount of researching (even though I wasn’t sure what exactly I was looking for), I have come here to try and explain my problem, so here it goes.

Basically I am just trying to figure out how to align movie clips to a certain position in the browser, not the stage. there are sites where it doesn’t matter how large your browser window is, movie clips will align to the top, left, right, or lower bottom (to the edge) to any browser window size even if it is being resized. Here are some examples:

(right corner movie clip)
http://andco.dk/?#AndCo

(bottom movie clip)

(best example of menu ALWAYS staying at the bottom of the window)

So basically,

A)What is this reffered to? B) does anyone know how to do it and C) am I over thinking it?

This is “in” right now, and if I can figure it out, possibilities are endless design wise, no more sticking to a default stage.

Also anyone know if there is a tutorial on this that explains in detail steps A-Z?

Thanks in advanced, you guys rock.